- Create a VM.- Install the OS on the VM.- Install Oracle on top if the host in the VM.- Create a database using DBCA with the same name/sid.

When you want to do the switch:

- Shut down both databases (original and VM one).- Delete the controlfiles, datafiles, tempfiles, redo logs etc. from the VM.- Copy the files from the original machine to the VM.- Start the DB on the VM.- If the positions of the files have changed (directory paths not the same) rename them. (http://www.oracle-base.com/articles/mis ... -files.php)